Tests portability: umount(8)

1) Avoid hangs on unmounting NFS on NetBSD

NetBSD umount(8) on a NFS mount whose server is gone will wait forever
because umount(8) calls realpath(3) and tries to access the mount before
it calls unmount(2). The non-portable, NetBSD-specific umount -R flag
prevent that behavior.

We therefore introduce UMOUNT_F, defined as "umount -f" on Linux and
"umount -f -R" on NetBSD to take care of forced unmounts, especially
in the NFS case.

2) Enforce usage of force_umount wrapper with timeout

Whenever umount is used it should be wrapped in force_umount with
tiemout handling. That saves us timing issues, and it handles the
NetBSD NFS case.

3) Cleanup kernel cache flush.

We used (cd $M0 && umount $M0 )	as a portable kernel cache flush
trick, but it does not flush everything we need on Linux. Introduce
a drop_cache() shell function that reverts to previously used
echo 3 > /proc/sys/vm/drop_caches on Linux, and keeps
(cd $M0 && umount $M0 ) on other systems.

BUG: 1129939
Change-Id: Iab1f5a023405f1f7270c42b595573702ca1eb6f3
Signed-off-by: Emmanuel Dreyfus <manu@netbsd.org>
Reviewed-on: http://review.gluster.org/11114
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/tests/include.rc b/tests/include.rc
index 2c45873aec0..32d60b43348 100644
--- a/tests/include.rc
+++ b/tests/include.rc
@@ -35,6 +35,7 @@ H0=${H0:=`hostname`}; # hostname
 MOUNT_TYPE_FUSE="fuse.glusterfs"
 GREP_MOUNT_OPT_RO="grep (ro"
 GREP_MOUNT_OPT_RW="grep (rw"
+UMOUNT_F="umount -f"
 
 PATH=$PATH:${PWD}/tests/utils
 
@@ -46,6 +47,7 @@ NetBSD)
   MOUNT_TYPE_FUSE="puffs|perfuse|fuse.glusterfs"
   GREP_MOUNT_OPT_RO="grep (read-only"
   GREP_MOUNT_OPT_RW="grep -v (read-only"
+  UMOUNT_F="umount -f -R"
   ;;
 *)
   ;;
@@ -456,7 +458,10 @@ function cleanup()
         Linux)
                 flag="-l"
                 ;;
-        NetBSD|FreeBSD|Darwin)
+        NetBSD)
+                flag="-f -R"
+                ;;
+        FreeBSD|Darwin)
                 flag="-f"
                 ;;
         *)